USTA Forehand & Backhand Biomechanics 2 — Questions and Answers
Question 1: During the forehand swing, which plane of motion does trunk rotation primarily occur in?
- Frontal plane
- Transverse plane (Correct answer)
- Sagittal plane
- Coronal plane
Correct answer: Transverse plane
Trunk rotation during the forehand occurs primarily in the transverse (horizontal) plane as the torso rotates around the vertical axis.
Question 2: What is the primary role of the non-dominant arm during a two-handed backhand?
- It provides all of the racket-head speed
- It acts as a guide while the dominant arm generates power
- It counterbalances trunk rotation and contributes significantly to power (Correct answer)
- It stabilizes the grip only
Correct answer: It counterbalances trunk rotation and contributes significantly to power
On the two-handed backhand the non-dominant arm drives rotation and contributes substantially to swing power while also counterbalancing the body.
Question 3: At contact on a topspin forehand, the racket face should ideally be oriented how relative to vertical?
- Perpendicular (90°) to the ground
- Slightly closed (tilted forward ~5–10°) (Correct answer)
- Slightly open (tilted backward ~5–10°)
- Fully horizontal (parallel to ground)
Correct answer: Slightly closed (tilted forward ~5–10°)
A slightly closed racket face at contact, combined with low-to-high swing path, imparts topspin on the ball.
Question 4: Which muscle group is primarily responsible for internal shoulder rotation in the acceleration phase of a forehand groundstroke?
- Rotator cuff external rotators
- Pectoralis major and subscapularis (Correct answer)
- Trapezius and rhomboids
- Posterior deltoid
Correct answer: Pectoralis major and subscapularis
The pectoralis major and subscapularis drive internal shoulder rotation during the forward acceleration phase of the forehand.
Question 5: On a one-handed backhand, the hitting shoulder should be positioned how at contact to maximize power transfer?
- Parallel to the baseline
- Pointing toward the target (open stance)
- Perpendicular to the net with hitting shoulder forward (Correct answer)
- Facing the net fully (square stance)
Correct answer: Perpendicular to the net with hitting shoulder forward
A closed or semi-closed stance with the hitting shoulder rotating through and forward at contact maximizes kinetic chain transfer on the one-handed backhand.
Question 6: What does 'trophy position lag' refer to in the context of groundstroke biomechanics?
- The delay of racket-head speed behind the wrist during the backswing
- The wrist and racket lagging behind the forearm during the forward swing to store elastic energy (Correct answer)
- A late unit turn causing timing errors
- The pause between backswing and forward swing
Correct answer: The wrist and racket lagging behind the forearm during the forward swing to store elastic energy
Racket-head lag describes the wrist and racket trailing the forearm during the forward swing, storing elastic energy that releases at contact for added speed.
Question 7: Which footwork pattern best supports an open-stance forehand from a biomechanical perspective?
- Cross-step followed by a split-step landing
- A wide lateral shuffle ending with weight loaded on the outside foot (Correct answer)
- A forward diagonal step closing the stance
- A side-step closing the stance with feet parallel to baseline
Correct answer: A wide lateral shuffle ending with weight loaded on the outside foot
An open-stance forehand requires loading the outside (right for right-hander) leg so that hip rotation can drive the kinetic chain from a stable base.
USTA Forehand & Backhand Biomechanics 2
During the forehand swing, which plane of motion does trunk rotation primarily occur in?